This invention relates to improvements in electrical connections to rail and the like, and more particularly to certain improvements in the connection, system, and clamps shown in prior United Kingdom application Serial No. 9317807.7, filed Aug. 27, 1993.
In such prior application there is shown a method of brazing a copper block to the rail by clamping a refractory mold or crucible against the block, igniting an exothermic material within the mold, with the heat created passing through a heat transmitting wall of the mold, and the block to elevate the temperature of brazing materials positioned between the block and rail. The block is provided with one or more holes, some of which may be tapped to enable an electrical connection readily to be made to the block and thus the rail. The reaction products of the high heat producing exothermic materials are contained in the mold or crucible which may be cleaned out and used again, or disposed of with the mold or crucible.
In such prior application two types of clamps are illustrated, one being a spring clamp which clamps under the rail, and the other a complex toggle. Both require a number of adjustments or preparations in order to be used properly. Both at times could use a person with more than two hands. They are time consuming and awkward to handle, set up, and install. All of this is complicated by the fact that the rail surface has to be prepared and that the block should be precisely located on the rail. A further complication is that the connections are often made or repaired under traffic, or between trains which can be frequent.
It is accordingly important to have a clamp for such a system which requires minimal or no adjustment, which can precisely locate the block with respect to the rail, and which can be attached to the rail quickly, yet also released quickly, for traffic clearance, for example. It is of course desirable that the clamp not go under the rail which would require dislocation of the ballast. It is, however, most important that for each installation a uniform ideal pressure be obtained between the mold, copper block and rail.